**Common Data :**** V _{DD} = 1.8V , L_{min} = 0.18µm, µ_{0N} = 350cm^{2}/V s, µ_{0P} = 100cm^{2}/V s,
|V_{TH} | = 0.55, t_{ox} = 3.8nm, λ = 0.07V^{−1}, χ = 0.1.**

**Common Data :**** V _{DD} = 1.8V , L_{min} = 0.18µm, µ_{0N} = 350cm^{2}/V s, µ_{0P} = 100cm^{2}/V s,
|V_{TH} | = 0.55, t_{ox} = 3.8nm, λ = 0.07V^{−1}, χ = 0.1.**

1. Consider the amplifier in Fig. 27, where of the transistors are and that of are Given

- Calculate the poles at nodes and , if and Also calculate the phase margine for unity gain feedback.
- How will you redesign the amplifier to have a phase margine of ?
- Calculate the slew rate of the opamp for b part only.

Figure 27: Figure for Question 1

2. An amplifier has forward gain of with two poles at and frequencies.

- For find the phase margine with unity gain feedback if
- If the unity gain closed loop amplifier exhibits a frequency peaking of near the gain crossover frequency, then what is the phase margine?

3. Consider the circuit shown in Fig. 28

- What is the advantage of using transistors and ?
- Determine the of the opamp .
- Derive the maximum output swing
- Derive the value of needed for a phase margine of 60
^{o}at unity gain feedback when - Determine the slew rate of the opamp

Figure 28 : Figure for Question 3

4. Consider the opamp shown in Fig. 29

Figure 29 : Figure for Question 4

- Calculate the gain of opamp if and for
- Calculate the output swing of the opamp
- Calculate slew rate if and
- and
- and

5.Design a PMOS input stage two stage opamp. The specifications to be met are , . Assume and stability needed is

6.Consider the amplifier shown in Fig. 30 employing a cascode stage as a amplifier. Assume node is dominant. Sketch the frequency response and explain how the circuit can be compensated .

Figure 30: Figure for Question 6

- If the circuit is modified as shown in Fig. 31, then sketch the frequency response for

Figure 31: Figure for Question 6

- If the circuit is modified as shown in Fig. 32, then sketch the frequency response for and

Figure 32: Figure for Question 6